This is a bit random, but do publishers like Penguin move a lot of classics each year? Middlemarch’s rank in the Amazon USA list would seem to indicate it sells around ten copies a day. Does that seem reasonable? I thought it seemed a bit low, but my opinion is truly random. There are >12 different paperback editions, so that would seem to argue for popularity…
As a reader, I only buy books new specifically when I want to support the author. Otherwise, I buy used or get it from the library.